Dual-in-line packages (DIP) have found wide use as a means of providing a mounting and interconnection for a variety of integrated circuits. In microelectronics circuits employing a plurality of DIPs, severe noise transients can arise in the power supply circuit due to the very fast switching times of some circuits. One method of preventing the coupling of this undesired high frequency interference into the rest of the circuit is to use low pass filters between the common power supply and the leads attached to the DIPs.
To effect such decoupling, it had been common practice to assemble capacitors on the printed circuit board and then connect such capacitors by conductive traces to the DIP leads corresponding to the power supply connection and ground pins. This procedure has been found to be disadvantageous for at least two reasons. First, it is wasteful of space as the discrete capacitive components are spread out on the printed circuit board and, second, the inductance of the connective conductive traces can nullify the effect of the capacitor in the circuit.
To overcome these disadvantages, the more current art has seen efforts in combining the decoupling capacitor to the DIP or to sockets for joining the DIPs to printed circuit boards. For example, in U.S. Pat. No. 3,880,493 issued to Lockhart, Jr. on Apr. 29, 1975, a decoupling capacitor is encapsulated in the body of a socket for interconnecting a DIP and a printed circuit board. Another example is shown in U.S. Pat. No. 3,912,984 issued to Lockhart, Jr., et al. on Oct. 14, 1975 where an auxiliary circuit package containing a decoupling capacitor is designed to occupy the open space between the rows of terminals of a DIP, the contacts of the auxiliary package and the terminals of the DIP being located simultaneously in contact with sockets on a printed circuit board. A further example is disclosed in commonly-owned U.S. Pat. No. 4,356,532 issued to Donaher, et al. on Oct. 26, 1982 wherein a substrate supporting capacitive components is connected by conductive traces thereon to the contact elements in a DIP receiving receptacle.
While all these current approaches minimize the areas on the printed circuit boards for connection of the decoupling components, they present other disadvantages. In the '493 patent, the encapsulation of the capacitor in the socket prevents ease of maintenance or repair of such component circuit, requiring a costly discarding of the entire socket if replacement is necessary. In the '984 patent, unnecessary terminals of the auxiliary package are provided and means for orienting such terminals relative to the contacts of the DIP is required. In the '532 patent, connection of the planar ear portions of the substrate to surfaces other than flat contact surfaces may provide difficulty in achieving a suitable connection.
Accordingly, it is desirable to provide a technique for interconnecting a decoupling component that not only minimizes real estate on a printed circuit board but is low cost and easy to handle and interconnect.